Gautham Kolluri

Development of a new method for sperm RNA purification in the chicken

Currently RNA transcripts are being used as male fertility biomarker for many mammalian species, but research work on chicken is at halt because classical RNA isolation methods are not effective for chicken spermatozoa. Hence, attempts have been made to optimize RNA isolation protocol from chicken sperm by using different methods, and to confirm the presence of sperm-specific transcripts of PRM and PLCZ1. Semen samples were centrifuged at low speed for removing debris like uric acid. Further, 1mL diluted semen was gently placed over 40% PureSperm or 45%/90% Percoll, and centrifuged to remove somatic cells and immature diploid spermatocytes. RNA was isolated from sperm by using RNAzol or TRIzol reagent or RNeasy Micro kit with certain modification, and RNA quantity and quality were evaluated. RNA isolated by using RNAzol or RNeasy Micro Kit yielded good quantity and quality of RNA for downstream applications compared to TRIzol. 40% PureSperm was found effective in removing somatic cells. RT-PCR results showed that sperm RNA samples were negative for CD4 and PTPRC. All the sperm RNA samples were positive for PRM and PLCZ1, markers of sperm RNA.

Bisphenol A reduces fertilizing ability and motility by compromising mitochondrial function of sperm

Bisphenol A (BPA) acts as an endocrine disruptor, affects animal reproductive success in vivo and affects sperm functions in vitro at environmentally relevant concentrations, leading to reduction in sperm motility and fertilizing ability in fish. The effect of in vitro BPA on avian sperm functions has not been explored. The present study examined the effect of environmentally relevant concentrations of BPA (0 mM, 0.18 mM, 0.37 mM, and 0.74 mM) on sperm functions in chicken in vitro. Sperm were exposed to concentrations of BPA for 30 min and analyzed for motility, fertilizing ability, live sperm percentage, and mitochondrial membrane potential (Δψm). Results showed that BPA at a concentration of 0.74 mM significantly decreased motility, fertilizing ability, live sperm count percentage, and sperm Δψm. Sperm motility was positively correlated with fertility (r = 0.73, p ≤ 0.01), live sperm percentage (r = 0.64, p ≤ 0.01), and high Δψm (r = 0.44, p ≤ 0.01). A dose-dependent and time-dependent effect of BPA was observed on sperm motility at all BPA concentrations. However, sperms fertilizing ability was unaffected in low BPA concentration (0.18 mM and 0.37 mM). A significantly higher percentage of moribund sperm was observed at 0.37 mM and 0.74 mM BPA compared with at 0.18 mM BPA, in the negative control, and in the vehicle control. The present study confirms that environmentally relevant concentrations of BPA are capable of compromising sperm functions, leading to reduction in fertilizing ability of chicken sperm.

Exploring alternatives to antibiotics as health promoting agents in poultry- a review

Poultry industry has undergone rapid growth during last three decades. For which even higher usage of antibiotics, both as growth promoters as well as therapeutic agents, has been adopted. However, due to the fear of resistance development in bacterial populations to antibiotics, presence of antibiotic residues in poultry products and increasing consumer demand for products free from antibiotic residues, search for alternatives that could replace antibiotics without causing loss to productivity or product quality has accelerated. Such alternatives in poultry include the use of organic acids, probiotic microorganisms, prebiotic substrates that benefit proliferation of beneficial bacterial populations or synbiotic (combinations of prebiotics and probiotics) ensuring better production and maintaining health of the birds. Others include vitamins and minerals, herbal drugs, plant extracts, phytobiotics and antimicrobial peptides. Probiotic organisms provides competition to pathogenic organisms for intestinal colonizing sites, reduce the diversion of nutrients for harmful microbes and the toxins produced by them and stimulates the immune systems. Similarly, prebiotic offers an alternative, as it alters the intestinal microbes and immune system to reduce colonization by pathogens and allows proliferation of beneficial microflora in the gut. Even using synbiotic is a better strategy for enhancing poultry production, however, more research is needed for selection of probiotic, prebiotics or synbiotics either alone or in combination that can result in the selection of strains capable of performing effectively in the gastrointestinal tract. The contents of this review will be useful for researchers to enrich their knowledge on alternatives of antibiotics in poultry birds without compromising performance of birds and bird welfare. Ajit Singh Yadav 1, *, Gautham Kolluri 1 , Marappan Gopi 1 , Kumaragurubaran Karthik 2 , Yashpal Singh Malik 2 and Kuldeep Dhama 2

Effect of seasonal variation on respiration rate and core body temperature in Aseel and Kadaknath breed of chicken

Native birds are more tolerant to adverse climatic conditions than the improved/cross-breeds of chicken. The present study was conducted to record the physiological responses such as respiration rate and body temperatures in Aseel and Kadaknath birds up to 6 weeks of age under standard managemental conditions during hot-humid and winter season. The dry-bulb temperature and wet-bulb temperature was recorded daily and temperature humidity index (THI) was calculated. The THI ranged from 73.33±1.61 to 85.70±0.33. Above 80 THI was observed during hot-humid season. The season, sex and breed interaction had highly significant (P<0.01) effect on body temperature (core and surface) and respiratory rate for all age groups. Season effect (P<0.05) was highly significant on studied parameters. It may be concluded that enhanced THI caused the elevation in surface and core body temperature along with increased respiration rate during hot-humid season, thereby indicating stressful conditions in native birds.

Baruscapillaria obsignata: a serious cause of enteropathy and high mortality in turkeys (meleagris gallopavo)

ABSTRACT Background: Capillariasis, an important parasitic disease of birds is caused at least by seven different genera of trichurid nematodes with clinical outcome ranging from mild enteritis to high mortality. Objective: This study was aimed to investigate the causative agent involved in high mortality associated with severe enteric illness among turkey flocks in an organized commercial poultry farm at Bareilly, India. Materials and Methods: Turkey carcasses (n = 119) and fecal samples from the affected deep litter pen constituted as the study materials. The disease was investigated by systematic necropsy, direct microscopy and histopathology. Representative samples were screened for other enteric pathogens. Results: Microscopic examination of mucosal scraping revealed capillarid worms and their eggs in all the samples. The morphological features of adult worms were typically consistent to Baruscapillaria obsignata. Histopathology exhibited thickened muscular and mucosal layers, mononuclear and heterophilic infiltration in the lamina propria, blunting and clubbing of villi, epithelial denudation and sections of capillarid worms. Administration of levamisole at 80 ppm in drinking water reduced the mortality, clinical illness and worm load after three days of therapy. Conclusions: The capillarid worms in different avian hosts can cause different clinical manifestations and outcomes. From India, this is the first report describing intestinal pathology caused by B. obsignata in turkeys. We conclude that the B. obsignata infection is capable of causing life threatening enteropathy in turkeys and, hence, routine screening, scheduled deworming and good litter management are crucial to control the infection and its associated loss.